When it comes to the difference between US presidential campaigning and reality, the gap is often widest when it comes to international trade. Leaders in Beijing, Hong Kong and elsewhere in the region have learned that what happens on the campaign trail often bears little relationship to the complexities of the White House. In 1992, then-Arkansas governor Bill Clinton railed against the threat of doing business with the 'butchers of Beijing' as he campaigned against president George H.W.Bush. By 2001, however, Mr Clinton left office with a record of having significantly improved ties with China, particularly on the economic front. Mr Clinton pushed the passing in Congress of Most Favoured Nation trading status for China in 1999, which helped its membership in the World Trade Organisation in 2000. In the 2000 election George W. Bush, then governor of Texas, campaigned as a pro-business free trader. But within two years he ordered punitive tariffs slapped on steel imports to the US - a move to protect local steel firms that quickly hurt China as well as South Korea and Japan. It is no surprise, then, that Democratic presidential hopeful Barack Obama's statements on free trade are getting close scrutiny amid his solid lead in the polls over Republican John McCain, a veteran senator with strong free-trade credentials. Less is known about the trade views of Senator Obama, who at 47 is one of the fastest-rising stars ever to emerge on the presidential stage. Some free traders and foreign diplomats have watched with concern as Senator Obama talks of levelling the playing field for American workers and questioning trade agreements with China and South Korea. These have been some of the only references to China in the campaign - a contrast to recent elections. In his final debate with Senator McCain last week, Senator Obama branded Beijing a currency 'manipulator' and slammed the recent US-South Korea trade agreement, which has still to be approved by the US Congress. Yet trade analysts suspect the Illinois senator is not quite as hard-edged as he appears. For all his inexperience, he may be proving he is a master politician - able to seamlessly talk out of both sides of his mouth when it comes to trade. Just consider statements he made in April attacking trade deals with China and South Korea. His audience was the AFL-CIO, America's biggest union organisation. Then they were leery of Senator Obama and drawn to his Democratic primary rival, Hillary Rodham Clinton. Now, however, their formidable resources are stumping for Senator Obama across swing states. And when he questions Most Favoured Nation trading status with China, he is really saying nothing. That status has long been a fait accompli, a decision that Senator Obama had no part in. It is a reminder, too, that in Senator Obama's formal political writings, he casts himself as a free trader, one who understands the benefits to local business and consumers of importing things more cheaply than they could be produced domestically. In his manifesto, The Audacity of Hope, he talks of how important free trade and globalisation have been to both the US and the world in the decades since the second world war. 'Barack Obama is clearly more moderate a force for free trade than he is on the campaign trail, no question,' said Daniel Griswold, director of the Centre for Trade Policy Studies at the Cato Institute, a pro-free market Washington think-tank. 'He's playing to his Democrat and union base. That's a fact of campaign life for him at this point.' Yet Mr Griswold says East Asian leaders should be prepared for a distinct change in tone in US trade policy. 'I don't think that the US would be initiating any sweeping trade liberalisation moves. But I think there'll still be an emphasis on enforcing agreements already in place.' While basic trade relations are unlikely to be affected, it is almost certain an Obama presidency would tackle intellectual property and environmental and labour standards. Of particular concern to China could be more intensive anti-dumping actions through the World Trade Organisation. The deal signed between Washington and Beijing paving the way for its WTO entry insisted that China still be classed as a 'non market economy' when it comes to dumping investigations. That essentially lowers the threshold and makes it easier for US firms to prove dumping - flooding a market with goods selling for lower than their cost of manufacture - is taking place. Interestingly, sources in the McCain camp like to talk up the differences over trade with Senator Obama. But inside the Obama campaign, they insist there is little to tell them apart.